1. Field of the Invention
This invention relates to connectors for coaxial cable and, more particularly, to a method and assembly for connecting a coaxial cable to an externally threaded connecting part so as to avoid unauthorized separation of the coaxial cable from the externally threaded connecting part.
2. Background Art
Coaxial cable is used in cable television systems (CATV), subscription television systems (STV) and master antenna television systems (MATV). It is common to connect coaxial cable in these systems using releasable connectors at a splice or drop location. To avoid unauthorized separation of a coaxial cable end connector, as might permit an unauthorized diversion of a cable signal, various tamper-proofing systems have been devised in the industry. As one example, U.S. Pat. No. 5,723,818 (Yeh) discloses a stepped diameter, cylindrical body which fully covers an “F” connector, including the region of the connector which is crimped to the coaxial cable end. A clamping element blocks withdrawal of the cable end, with the connector thereon, from the body. The system is set up with the end connector pre-attached to the coaxial cable. A special tool is directed through the clamping element to engage a polygonally-shaped outer surface of a rotatable nut on the connector to effect rotation thereof.
Each of U.S. Pat. No. 4,053,195, to Laverick et al (Laverick), and U.S. Pat. No. 4,168,921 (Blanchard) discloses a cup-shaped sleeve which covers a rotatable nut on a connector so that radial access thereto through a conventional wrench is prohibited. A turning tool is directed axially through the open end of the sleeve to engage a polygonally-shaped surface of the nut. In Both Laverick and Blanchard, the end connector is crimped to the cable end before installation of the sleeve.
In Laverick, Blanchard, and Yeh, a special tool having cantilevered legs is required for operation. Due to the axial extent of the protective structure in each, these legs must be relatively long and are thus prone to deformation as a torquing force is applied to the tool. This may prevent removal, through the tool, of a connection that is locked in place due to corrosion or held firmly by reason of the nut thereon being turned tightly into place in the initial installation.
U.S. Pat. No. 4,469,386 (Ackerman) discloses a coaxial plug which is held in place by a specially designed cap that is threaded upon an externally threaded connecting part. The cap is designed to be turned by a complementary tool, which is required to be directed into a cavity occupied by the cap.